Injection Molding Machine
An injection molding machine (also spelled as injection moulding machine in British English), also known as an injection press, is a machine for manufacturing plastic products by the injection molding process. It consists of two main parts, an injection unit and a clamping unit. See Injection Molding Machine and Hobby Injection Molding on Wikipedia.
Maker Nexus has a Mini-Jector Model 55P injection molding machine. It is <<insert dimensions here>> and weighs <<insert approximate weight here>>. It can mold parts up to 54x146x24mm.
- Heating System
- One nozzle heater
- Two barrel heaters
- Hydraulic System
- Twin injection cylinders
- One carriage cylinder
- Self contained hydraulic power unit features:
- 5.4 gallon reservoir
- 1725 RPM motor with 2 HP
- 2.0 GPM gear pump immersed in the reservoir
- Control System
- Siemens PLC/HMI
- Packing Mode
- Purge Cycle
- Directional and control valves with plug-in connectors that control:
- Screw speed
- Injection speed
- Screw back pressure read on oil filled gage
- Manual and semi-automatic modes
- Motor starter with thermal overloads and emergency stop button
- Selectable de-compression feature
- Carriage speed
- Additional Features
- Aluminum material hopper with shut off and dump tube
- Moving parts covered by safety shroud
- Heat shield on barrel
- Greaseless bushings used in screw unit mechanism
- Provision for cooling feed throat
The machine uses 2-part molds made from two 6" x 2 3/18" x 3/4" aluminum blocks with a 3/8" round fillet at the corners. The mold is placed in the machine jaws, which clamp the 2 parts together for each injection. Currently Maker Nexus does not have a CNC mill for producing aluminum molds, so we are working on some alternatives:
- We are working on an aluminum frame that can be used to make a silicone mold and hold it in place in the machine.
- Once our resin 3D printer is online, we will be able to print molds entirely in resin.
Mold Design Resources
- Basilius' Injection Molding Quick Guide
- Demo of creating a silicone mold in a frame from TheCrafsMan SteadyCraftin
Greasing Grease Fittings
For your convenience, here's what it says about greasing the grease fittings: "The machine requires very little in the way of lubrication, as the injection plate and thrust housing bushings are a composite semi-greaseless type that require lubrication once every 6 months to a year. The thrust housing has two linear bushings; one accessible from the front, one from the rear. The injection cylinder plate also has two bushings with staggered access. Use a lithium-based grease and inject only enough grease to force the old grease out. This removes any dirt accumulated in the bushings. Wipe the old grease off of the guide rods."
( add link to our BOSS class document )
Tips and Tricks
- (things you'd want to know)
Members can access all of the manufacturer's reference materials on the MN Members Drive here.